NXP Semiconductors K22F series - Chapter 32 Cyclic Redundancy Check (CRC); Introduction; Features; Block Diagram

Chapter 32
Cyclic Redundancy Check (CRC)
32.1 Introduction
NOTE
For the chip-specific implementation details of this module's
instances, see the chip configuration information.
The cyclic redundancy check (CRC) module generates 16/32-bit CRC code for error
detection.
The CRC module provides a programmable polynomial and other parameters required to
implement a 16-bit or 32-bit CRC standard.
The 16/32-bit code is calculated for 32 bits of data at a time.
32.1.1
Features
Features of the CRC module include:
• Hardware CRC generator circuit using a 16-bit or 32-bit programmable shift register
• Programmable initial seed value and polynomial
• Option to transpose input data or output data (the CRC result) bitwise or bytewise.
This option is required for certain CRC standards. A bytewise transpose operation is
not possible when accessing the CRC data register via 8-bit accesses. In this case, the
user's software must perform the bytewise transpose function.
• Option for inversion of final CRC result
• 32-bit CPU register programming interface
32.1.2
Block diagram
The following is a block diagram of the CRC.
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 741